Oligosaccharides will be isolated from natural sources. Oligosaccharides will be coupled to macromolecules in order to make antibodies specific for certain sugar sequences. The antibodies will be used in radioimmune assays for the occurrence of these sugar sequences in the glycolipids and glycoproteins of cell membranes and serum in order to investigate the involvement of the complex carbohydrates of cell surfaces in development and regulation or as tumor-specific antigens. Waldenstrom macroglobulins and myeloma proteins will be screened for their ability to react with human erythrocytes. Those that do will be tested for their ability to react with various oligosaccharides coupled to macromolecules. Carbohydrates on cell membranes that are receptors for toxins, hormones, and antibodies will be isolated and characterized.